Officials unveiled a proposal to simplify Seattle-based King County Metro Transit’s fares, establishing a single $2.75 fare for all adult passengers, no matter the time of day or where they travel in King County. The proposed ordinance also would increase assistance for passengers who earn a lower income.

Metro currently has one of the most complex fare structures in the nation, with one zone for the City of Seattle and another for all areas outside the city, as well as extra charges during the morning and evening commute.

One-third of riders in a recent survey said the current system is too complex and difficult to understand.

About 65% of Metro customers will see no change or a fare reduction, according to boarding data.

If the King County Council approves the proposed ordinance, it could take effect as soon as July 2018.

An estimated 35% of Metro boardings take place during off-peak hours, and those passengers would pay 25 cents more.

• 21% of off-peak riders pay full adult fares without any subsidy or employer-sponsored pass.

• 14% of off-peak riders use employer or organization-sponsored transit passes.

• About 31% of Metro riders qualify for ORCA Lift, youth, senior and disabled fares. They would see no change.

The ordinance would include additional funding to help passengers who earn very low incomes not covered by the reduced fare system, ORCA Lift and passengers least able to pay during off-peak hours:

• Increased funding for the Human Services Ticket Program, from $3.6 million to $4 million, to offset higher cost for social service agencies that distribute discount tickets.

• Forty-four percent of tickets sold through the program are for off-peak trips.

• Working with ORCA partners to reduce fees for adult and youth ORCA cards and eliminate the $3 card fee for seniors and people with disabilities.

• Continuing to work with schools, colleges and universities to enhance fare programs for students.